Patent GB-708242-A (GB)
Title: Improvements in or relating to glass panels
Inventor: HALL HENRY WARBURTON
IPC: B32B17/10
Filed: 1950-03-09
Abstract: 708,242. Compound glass. NATIONAL RESEARCH DEVELOPMENT CORPORATION. March 30, 1951 [March 9, 1950], No. 6003/50. Class 140 A laminated glass panel comprises at least three plastic material core layers sandwiched between two glass layers and along part at least of the periphery of the panel at least one intermediate layer of the core terminates some distance from the edges of the glass panels, whilst two outer layers at least of the core extend some distance beyond the edges of the glass panels, at least one layer of fibrous material impregnated with plastic setting materials being interposed as a reinforcement between the margins of the said extending layers of the core and abutting against the edge(s) of said intermediate layer(s) of the core and being secured adhesively in position. Further alternate layers of plastic material and of fibrous material impregnated with plastic setting material may be built up upon the outer faces of the projecting margins of extending layers of the core, some of these built-up layers abutting against the edges of the glass panels and some of them extending over the outer faces of the margins of the glass panels, all the layers being secured adhesively in position. The plastic material may be of any type commonly used in the laminated basic glass panels and the plastic setting materials may be of any convenient, e.g. thermosetting, type capable of setting from liquid form. As shown in Fig. 1 the panel has two outer layers 11, 12 of glass and four core layers 13, 14, 15, 16 of polyvinyl butyral sheet all secured adhesively together in known manner, the edges of the two inner layers 14, 15 of the core lying between the two glass layers 11, 12 some distance from the edges of the latter, but the two outer layers 13, 16 of the core extending some distance beyond the edges of the glass layers 11, 12 as indicated at 13a, 16a. Between these margins of the outer core layers 13, 16 is accommodated a strip of glass fibre cloth 17 which extends from the edges of the inner core layer 14, 15 between the glass layers 11, 12 to the edges of the outer core layers 13, 16 and is secured adhesively to the margins of the latter. The glass fibre cloth 17 may be impregnated with, or embedded in, polyvinyl butyral which may be united integrally (by suitable heat and pressure) with that of the outer core layers 13, 16 and preferably with that of the inner core layers 14, 15 as well. It is not essential that the glass fibre cloth 17 may be impregnated with the same material as that of the core layers 13, 14, 15, 16 or at all. As shown in Fig. 2 the panel comprises two outer layers 21, 22 of glass and four core layers 23, 24, 25, 26 of polyvinyl butyral, the outer core layers 23, 26 extending beyond the edges of the glass layers 21, 22 as indicated at 23a, 26a and a strip 27 of glass fibre cloth accommodated between their margins abuts against the edges of the inner core layers 24, 25 between the glass layers 21, 22. Further alternate layers of glass fibre cloth 28-33 and of polyvinyl butyral 34-39 are added, the layers 28, 34, 30 and 29, 35, 31 abutting against the edges of the glass sheets 21, 22 respectively and the remaining layers 36, 32, 38 and 37, 33, 39, being wider and extending over the margins of the glass sheets 21, 22 to which the polyvinyl butyral layers 36, 37 respectively are adhesively secured. The glass fibre cloth layers 27-33 are adhesively secured to the polyvinyl butyral layers 23-26, 34-39 respectively as shown and any or all of'the glass fibre cloth layers 27-33 may be impregnated with or embedded in polyvinyl butyral which may be united integrally with that to which the glass cloth layers adhere, so that there may in effect be one mass of polyvinyl butyral with pieces of glass cloth reinforcement embedded therein.